1. Field
This disclosure relates to optical communications networks and more particularly to optical circuit switches using MEMS (micro-electromechanical system) mirror arrays.
2. Description of the Related Art
Communications networks commonly contain a mesh of transmission paths which intersect at hubs or nodes. At least some of the nodes may include a switching device that receives data or information arriving at the node and retransmits the information along appropriate outgoing paths.
Optical fiber links are commonly used to provide high bandwidth transmission paths between nodes. Such optical fiber links form the backbone of wide area networks such as the Internet. Optical fiber links are also applied in high bandwidth local area networks which may be used, for example, to connect server racks in large data centers or to connect processors in high performance computers.
An optical circuit switch is a switching device that forms connections between pairs of optical fiber communications paths. A typical optical circuit switch may have a plurality of ports and be capable of selectively connecting any port to any other port in pairs. Since an optical circuit switch does not convert information flowing over the optical fiber communication paths to electrical signals, the bandwidth of an optical circuit switch is essentially the same as the bandwidth of the optical communications paths. Further, since an optical circuit switch does not convert information into electrical signals, the power consumption of an optical circuit switch may be substantially lower than a comparable conventional (i.e. electronic) switch.
Throughout this description, elements appearing in figures are assigned three-digit reference designators, where the most significant digit is the figure number where the element is introduced and the two least significant digits are specific to the element. An element that is not described in conjunction with a figure may be presumed to have the same characteristics and function as a previously-described element having the same reference designator.